Well it's now spring and time to get cracking on this project. I've decided to extend the upper pond to 20' x 7' (maybe 20x8). The existing pond is 12'x7' and of that I will remove a 4x7 shallow section. This will give a full 20x7' pond that is 3' deep.
I am contemplating expansion of the lower pond as well, not so much in length but in width. It is currently 4 x 8' and I'd like to make it another foot wider to make it 5x8 and 1 1/2' deep. I'll have to see how the budget goes on the upper pond first.
Next steps are to calculate how much liner I will need, how much it will cost, and how much it will weigh! All are important factors. I will also need a small kiddie pool or make a temporary one with some liner material and 4x4's. I'm also contemplating putting all of the fish in the lower pond for a few days until I can get the upper one completed and full of water. That would be 11 large fish in a 4x8 pool.
I'm going to try and utilize a wooden frame around the top, possibly anchored to the retaining walls to help keep the edges from sinking when rocks are put around the edge. The other thing I will try to do is to raise it all slightly above ground level. This nailed me in the past during heavy rains. The silt would run into the pond and muddy the water for weeks.
More and pictures later once I get started.